diff --git a/README.md b/README.md
index 33c9119..da6bb20 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,8 @@ ToDo List:
 - [ ] add inclusive operators like '!=', '>=', '<='
 - [ ] add support for priority operators
 - [X] add input_number() std function
-- [ ] add type() std function
+- [ ] add null type (dirty way to handle no returns and some errors)
+- [ ] add type() std function and others type checking functions
 - [X] add ceil() and floor() std functions
 - [X] base of the CLI
 - [ ] evaluate expression from stdin
@@ -149,6 +150,7 @@ floor(nb)
 random_int(min, max)
 random_float(min, max)
 type(var) -> return the type of a var as int
+is_null(var)
 is_int(var)
 is_float(var)
 print_string(str)
diff --git a/examples/guessing.ltor b/examples/guessing.ltor
new file mode 100644
index 0000000..baaff52
--- /dev/null
+++ b/examples/guessing.ltor
@@ -0,0 +1,23 @@
+set i to 0
+set toGuess to random_int(0, 100)
+while 1 do
+    set guessed to input_number()
+    if i > 20 then
+        # do you really want to continue?
+        break
+    end
+    if guessed = toGuess then
+        # success
+        print_ascii(83)
+        break
+    end
+    if guessed < toGuess then
+        # too low
+        print_ascii(76)
+    end
+    if guessed > toGuess then
+        # too high
+        print_ascii(72)
+    end
+    set i to i+1
+end
diff --git a/src/funcs.c b/src/funcs.c
index af89baf..92696d6 100644
--- a/src/funcs.c
+++ b/src/funcs.c
@@ -134,7 +134,11 @@ int input_number_impl(int* res, unsigned char* resType, unsigned char* types, in
             return 0;
         }
     }
-    return 1;
+    // we didn't manage to parse the number
+    *resType = TYPE_INT;
+    *res = 0;
+    
+    return 0;
 }
 
 int simple_float_func(float (*func)(float), int* res, unsigned char* resType, unsigned char* types, int* args)